The invention relates to telecommunications and more particularly to a system and method for accessing different network access servers through a telecommunications system comprising a bearer network, service switching points and a service control subsystem. The network access servers may provide access to one or more intranet/extranet/internet networks and may be under the control of the same or different service providers, generically referred to below as xe2x80x9caccess service providersxe2x80x9d (ASPs). An access service provider ASP may provide services additional to simple network access such as chat rooms, bulletin boards etc; in the present specification the term xe2x80x9cISPxe2x80x9d is used to mean an access service provider providing internet access, whether or not additional services are also provided.
The explosive growth of the internet has lead to some arduous coexistence between two different worlds and services: a traditional world of telecommunication services coexisting with a new emergent world of information services.
The world of telecommunication services is that of the telecommunications operators, such as those running the traditional Public Switched Telephone Networks (PSTN) and the more recent Public Land Mobile Networks (PLMN). The last decade or so has seen important developments in traditional PSTNs including the introduction of the fully digital networks (particularly Integrated Service Data Networkxe2x80x94ISDN) and the emergence of new services and intelligence in the telecommunications. Examples of such services are the 800 number and call forwarding. The architecture of a modern PSTN is depicted in FIG. 1. Customer Premise equipments (CPE) 10 such as standard telephones or more recently ISDN terminals are connected to the network by dedicated transmission links, typically to a Local Exchange. An Exchange is often referred to as a Switching Point or SP. Each local SP is connected to a trunk Exchange that is also connected to other exchanges or SPs so as to form an inter-exchange network.
Generally speaking, the control function of the PSTN uses now a separate Common Channel Signalling network (CCS) based on the CCITT No 7 protocol suite. In FIG. 1, the signalling network is represented by reference number 16. When the Customer Premise Equipment CPE is a dumb telephone, the signalling at the access network may still be in-band signalling while in the case of a modern ISDN terminal, even at the level of the access network the signalling is conveyed through a path (D-channel) that is separate from the voice path constituted by the B-channels.
More recently, more intelligence has been introduced in the control or signalling function of the PSTN, and some SPs were replaced by more powerful and sophisticated Service Switching Points (SSP) 12 allowing new Intelligent Network (IN) Services. With respect to FIG. 1 again, a SSP 12 is arranged to suspend call processing at defined points-in-call upon particular criteria being met, and to generally delegate the continuation of the processing of the call to a Service Control Point (SCP) 13, generally remote, which forms a part of a Service Control Subsystem 15.
More particularly, when the SSP 12 receives a call, it examines trigger conditions as well as user information to ascertain whether the call requires a service to be provided in addition to the normal routing function. If a service is to be provided, the considered SSP messages the SCP 13 a request for that service. The Service Control Point may be associated with a Service Data Function (SDF) 14 permitting the use of subscriber information.
Typical examples of such higher level services are the above mentioned call forwarding services or still the 800 number services. The PSTN may be further enhanced by the use of Intelligent Peripherals (IP) which provides additional communication with the end-user, by means of voice announcements for instance. Service control functionality and IP functionality may also be combined in Service Nodes.
The above-described model for the provision of IN services in a PSTN can also be mapped onto PLMNs (Public Land Mobile Networks) such as GSM and other mobile networks. Control signalling in the case of a mobile subscriber is more complex because in addition to all the usual signalling requirements, there is also a need to establish where a call to a mobile subscriber should be routed; however, this is not a very different problem from a number of called-party IN services in the PSTN. Thus in GSM, the service data function (SDF) is largely located in a system named a Home Location Register (HLR) and the service control function in a system named a Visitor Location Register (VLR) that is generally associated on a one-to-one basis with each SSP (which in GSM terminology is called a Mobile Switching Centre, MSC).
Because subscribers are mobile, the subscriber profile is transported from the HLR to whichever VLR happens to be functionally closest to be mobile subscriber, and from there the VLR operates the (fixed) service using the subscriber profile and interacts with the SSP. The HLR and VLR thus constitute a service control subsystem similar to an SCP or Adjunct with their associated databases.
It is, of course, also possible to provide IN services in private telephone systems and, in this case, the service control function and service data function are generally either integrated into a PABX (Private Automatic Branch Exchange) or provided by a local computer. The service control subsystem, whilst present, may thus not be a physically distinct from the PABX.
In the following, the terms xe2x80x98bearer networkxe2x80x99, xe2x80x98service switching pointsxe2x80x99 and xe2x80x98service control subsystemxe2x80x99 will be used to refer not only to the respective elements of a PTSN but also unless the context demands otherwise to refer to the equivalent elements in a PLMN and other types of telephone networks.
U.S. Pat. No. 5,452,350 assigned to Advantis describes one example of an IN service, in this case relating to the routing of calls to a call center or similar resources. More particularly, the SCF of a PSTN queries a routing processor of the subscriber (e. g. call center) network to be told the number to which a call should be routed to access a particular resource (any PSTN termination, including ACD, IVR, modems and individual stations). The routing processor effects routing control in dependence on the identity of the caller (doing a lookup in a customer database) and xe2x80x9ccapacity percentagesxe2x80x9d representing a proportion of all calls for a desired resource that can be handled as indicated by feedback from the resource.
EP-A-0 654 930 (ATandT) entitled xe2x80x9cNetwork-accessible Intelligent Telephone Servicexe2x80x9d describes another example of an IN service, in this case for providing a user with a common way of accessing a variety of services from different telephone networks. More particularly, a central database is provided for holding user-related data (including service profile data for a number of services), this database being accessible (via SS7 links) from any of a plurality of telephone networks. When needed, service details are passed to regional processing nodes which then deliver services as required in the language specified. The service details delivered to such nodes may include the name and numbers of the user""s top called-numbers list which are then announced to the user to enable the latter to select a desired number to be called.
Although the architecture of the recent telecommunication networks have reached a high degree of sophistication, as shown in FIG. 1 and from the preceding example, the possibilities opened up by interaction with the newxe2x80x94and explosivexe2x80x94world of Information services are still being explored. The information services world covers all the electronic information distribution services that are made possible by the recent development and success of the Internet-based global applications, the best example of which being certainly the World Wide Web (WWW). In the perspective of Internet, anyone may become an information provider with a world-wide audience.
The mutual development of these two worlds of information and telecommunication services requires a higher and closer interaction between these in spite of their strong differences in culture. Some simple and very basic interactions have already been widely implemented. For instance, what is called a network access is the connection that one may have to the Internet network; since most users of the World Wide Web do not have direct network access to the Internet, they must access the network via an Internet Service Provider (ISP) that does have such a direct network access. In this case, the user generally communicates with the ISP over the PSTN using a modem and employing an appropriate protocol which allows the Internet packets to traverse the ordinary telephone lines. This example illustrates a very simple co-operation between the Internet world of information services and the telecommunication world: namely the setting up of a bearer channel over the PSTN for subsequently generated Internet traffic.
In a similar manner, enterprise users can use the public telephone infrastructure to access the enterprise computer network (xe2x80x9cintranetxe2x80x9d), generally through one or two levels of security.
The equipment used to enable access to an intranet, internet, or similar network via a telephone network is referred to herein as an access server or point of presence (POP).
Other techniques for increasing the interaction between the world of the communication services and that of the information services are described in Applicants published International Applications No:
PCT/GB96/03048 xe2x80x9cMethod of providing telecommunication servicesxe2x80x9d
PCT/EP98/01119 xe2x80x9cService Node for Providing Telecommunications Servicesxe2x80x9d
PCT/GB97/00469 xe2x80x9cMethod of making available content resources to users of a telephone networkxe2x80x9d
These applications show methods for retrieving service control data and logic over the internet for use in service provision, as well as methods for retrieving content over the internet for playback to telephone users.
The co-operation between the techniques carried out in the information services world and the telecommunications world needs to be improved. There is a strong desire for a higher degree of interaction between the worlds and techniques of Internet and telecommunications.
Consider for instance the situation of an user who wishes to get access to different networks or to different internet service providers"" for the different services they provide. With respect to FIG. 1 again, he may wish first to access public Internet network 30 through a selected ISP, and then to access an extranet network 40 of another ISP, and finally a private intranet network 20 which may be that of the company or the firm of which he is an employee.
With the techniques known in the art, the user is compelled to handle different and independent access procedures when he wants to have access rights to the different network access servers 45 involved in the foregoing example.
For each access, the user will have to dial into the public telephone network in order to call up his selected access service provider ASP, and consequently manage multiple telephone numbers and log-in procedures. Today customers typically subscribe independently to different ISPs. Those ISPs typically provide local phone numbers to ensure cheap network connections for the user. For mobile users, who need to connect from different geographical locations, this requires that the user has an up-to-date list of the ISPs"" local phone numbers. In response to this problem, telephone network operators now provide virtual local phone numbers, where calls to the numbers are charged at a local rate, even if called from a remote (ie non-local) area. However, the user is still required to know the virtual local phone number corresponding to each ISP to which he/she wishes to connect.
Additionally, as well as paying a connection fee to the telephone network operator, the user must maintain an account with each ISP. Each ISP will implement its own accounting scheme, typically based on a monthly or yearly subscription rate. Most ISPs have avoided imposing a per-usage billing scheme (such as exists in telephone networks) scheme because of the high cost involved in managing and maintaining such a billing scheme.
Finally, as employees become more mobile, and as telecommuting becomes more popular, companies often wish to arrange common access arrangements for all of their staff. An ISP may be interested in offering preferential tariff rates or enhanced quality of service guarantees to all employees of a company. This is particularly advantageous for companies where employees often work from outside the office, and need cheap and efficient communication links with the office. With such arrangements, it is important that the conditions of the arrangement (such as the tariff rates or the quality of service guarantees) can be enhanced or modified quickly, if necessary, and that such modifications can be applied simultaneously to all employees of the company. Furthermore, a company may have more that one agreement with an ISP, allowing additional access rights or QoS guarantees to certain employees.
It is an object of the present invention to enhance the ability of the service control subsystem of the telecommunications system to provide value-added services to users accessing network access servers, for example an ISP internet access server.
This and other problems are solved by the methods and apparatus which are defined in the accompanying claims.
Thus, in a preferred embodiment of the invention applied to a telephone system, a database holds data about different dial-up access services, for intranet/extranet/internet access, to which a user may have some access rights, as well as the different access parameters; this database is either part of the service control subsystem of the telephone system or is accessible to it. The telephone system provides a single telephone numberxe2x80x94known as the generic access number to activate a generic dialup access service. When a user calls the generic access number, the local SSP (or MSC) sends a request to the service control subsystem. The latter initiates an authentication procedure with the user, and once the user has been identified, the service control subsystem can retrieve the particular user""s profile from the database. This profile will include data about the access services for which the user has access rights. This data may directly identify the access service providers or may simply give the telephone numbers of the access servers to which the user subscribes. The data may include other access parameters (such as tariff rates and Quality of Service guarantees). The available access services can be presented to the user, and in accordance with the user""s choice and the corresponding information stored in the database, the service control subsystem can instruct the local SSP(or MSC) to connect the user to an appropriate access server. The choice of access server may be effected in whole or in part in dependence on external factors (such as time-of-day, access server availability, etc. ) not dictated by the user. When the connection is terminated, the service control subsystem is informed, allowing it to generate the appropriate accounting and billing data.
Thus, in at least a preferred embodiment, the invention provides a user with a single authentication, authorization and accounting point to access different internet and intranet networks, where that entry point is associated with a globally unique phone number.
Preferably, all the users belonging to a group or a company are commonly identified and group-wide criteria applied to access server selection or quality of service choice. This facilitates access service management for the group and may be extended to include the generation of a single bill for all such accesses from group members.